INTERNATIONAL STANDARD

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1 INTERNATIONAL STANDARD IEC Second edition Arc welding equipment Part 7: Torches This English-language version is derived from the original bilingual publication by leaving out all French-language pages. Missing page numbers correspond to the Frenchlanguage pages. Reference number IEC :2005(E)

2 INTERNATIONAL STANDARD IEC Second edition Arc welding equipment Part 7: Torches IEC 2005 Copyright - all rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland Telephone: Telefax: inmail@iec.ch Web: Commission Electrotechnique Internationale International Electrotechnical Commission Международная Электротехническая Комиссия PRICE CODE For price, see current catalogue U

3 IEC: CONTENTS FOREWORD Scope Normative references Terms and definitions Environmental conditions Classification General Process Guidance Cooling Main arc striking for plasma processes Test conditions General Type tests Routine tests Protection against electric shock Voltage rating Insulation resistance Dielectric strength Protection against electric shock in normal service (direct contact) Thermal rating General Temperature rise Heating test Pressure of the liquid cooling system Resistance to hot objects Mechanical provisions Impact resistance Accessible parts Marking Instructions for use...41 Annex A (informative) Additional terminology...45 Annex B (normative) Position of the welding torches for the heating test...51 Annex C (informative) Cooled copper block...53 Annex D (informative) Copper block with a hole...55 Annex E (informative) Copper bars with a slot...57 Figure 1 Device for testing the resistance to hot objects...37 Figure 2 Device for the impact test...39 Figure A.1 Torch for metal inert/active gas (MIG/MAG) and self-shielded flux-cored arc welding...47

4 IEC: Figure A.2 Gun for metal inert/active gas (MIG/MAG) and self-shielded flux-cored arc welding...47 Figure A.3 Torch for tungsten inert gas arc welding...47 Figure A.4 Torch for plasma arc welding...47 Figure A.5 Torch for plasma cutting...47 Figure A.6 Supply unit...47 Figure A.7 Mechanically guided plasma torch...49 Figure B.1 MIG/MAG torches...51 Figure B.2 TIG torches...51 Figure B.3 Plasma welding torches...51 Figure C.1 Water-cooled copper block Example...53 Figure D.1 Water-cooled copper block with a hole Example...55 Figure E.1 Water-cooled copper bars with a slot Example...57 Table 1 Voltage rating of torches...21 Table 2 Test values for metal inert gas arc welding (MIG) of aluminium alloys...29 Table 3 Test values for metal active gas arc welding (MAG) of mild steel...31 Table 4 Test values for metal active gas arc welding (MAG) with flux-cored wire...31 Table 5 Test values for self-shielded flux-cored arc welding of mild steel...33 Table 6 Test values for tungsten inert gas arc welding (TIG)...33 Table 7 Test values for plasma arc welding...35 Table A.1 List of terms...45

5 IEC: INTERNATIONAL ELECTROTECHNICAL COMMISSION ARC WELDING EQUIPMENT Part 7: Torches FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as IEC Publication(s) ). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and nongovernmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC has been prepared by IEC technical committee 26: Electric welding. This part of IEC is to be used in conjunction with IEC This second edition cancels and replaces the first edition published in 2000 and constitutes a technical revision. The main changes with respect to the previous edition are listed below: the scope includes relationship to IEC and a note is added (see Clause 1); normative references are updated (see Clause 2); a preliminary insulation resistance test is added (see item b) of 6.2); TIG and plasma torches now have an arc striking and stabilizing voltage rating (see 7.1, 7.3 and item c) of Clause 13);

6 IEC: a procedure to determine the arc striking and stabilizing voltage rating of plasma torches is given (see 7.3); requirements for plasma cutting torches are updated to harmonize with IEC :2005 (see 7.4.2); Heating test for liquid cooled torches and Instructions for use incorporate elements of IEC (see 8.3 and item e) of Clause 13); during the heating test, the gas flow tolerance has been modified (see Tables 2, 3, 4 and 6); the temperature of the hot wire is maintained during the Resistance to hot objects test (see Clause 10); accessible parts shall not have sharp edges, rough surfaces or protruding parts likely to cause injury (see 11.2); Instructions for use shall contain environmental conditions (see item h) of Clause 13). The text of this standard is based on the following documents: FDIS 26/308/FDIS Report on voting 26/312/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. IEC consists of the following parts, under the general title Arc welding equipment: Part 1: Welding power sources Part 2: Liquid cooling systems Part 3: Arc striking and stabilizing devices Part 4: Safety, maintenance and inspection of arc welding equipment in use 1 Part 5: Wire feeders Part 6: Limited duty manual metal arc welding power sources Part 7: Torches Part 8: Gas consoles for welding and plasma cutting systems Part 10: Electromagnetic compatibility (EMC) requirements Part 11: Electrode holders Part 12: Coupling devices for welding cables Part 13: Terms 1 The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under " in the data related to the specific publication. At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended. 1 Under consideration.

7 IEC: ARC WELDING EQUIPMENT Part 7: Torches 1 Scope This part of IEC specifies safety and construction requirements for torches for arc welding and allied processes. In this part of IEC 60974, a torch consists of the torch body, the cable-hose assembly and other components. This part of IEC is not applicable to electrode holders for manual metal arc welding or torches for air-arc cutting/gouging. NOTE In this part of IEC 60974, the terms "torch" and "gun" are interchangeable. For convenience "torch" has been used in the following text. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050(151), International Electrotechnical Vocabulary (IEV) Part 151: Electrical and magnetic devices IEC 60050(851), International Electrotechnical Vocabulary (IEV) Chapter 851: Electric welding IEC 60529, Degrees of protection provided by enclosures (IP Code) IEC , Insulation coordination for equipment within low-voltage systems Part 1: Principles, requirements and tests IEC :2005, Arc welding equipment Part 1: Welding power sources IEC , Arc welding equipment Part 2: Liquid cooling systems